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Discussion Starter · #1 ·
Hello,

I have a 1984 900i that I've owned for about 6 months. It has just over 176,000 miles. I took it into the shop a few days ago for a routine oil change - no issues going in. When the tech finished the oil change I noticed the car wasn't idling well at all. It kept stalling out. After some tinkering and a few test drives around the block, the idle issue was fixed and I paid up and went on my way.

Roughly a tank and a half of fuel later, I'm driving home in the wee hours of the morning today and notice the oil pressure light flicker periodically. The flickers were very quick and I (neglectfully) chose to keep on trucking.

By the time I arrived home the light had started to stay on for a few seconds at a time, although the car was running fine until I shut it off.
When I checked the oil, nothing was showing on the dipstick at all. I don't think I did any damage to the engine, but I realize it was stupid of me to keep driving after I saw the light. Oil under the bridge at this point.

After a few hours of sleep, I got up and put a few quarts of oil in and started Sally up. I noticed considerable smoking from the exhaust (white/gray smoke) and no signs of leaking from the filter or drain plug. Both the filter and drain plug were snug. After running a few minutes a closer look at the exhaust revealed drops of oil being spewed from the pipe.

My first question, which might be obvious to some of you, is what is going on with my engine and why is it burning oil? Second question: is it related to the oil change (and subsequent idle adjustment) I got on Tuesday? The car was running fine and not burning oil (to the best of my knowledge) before I brought it in.

Any help would be greatly appreciated.

Cheers,

Ryan
 

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1st the bad news. Oil pressure switchs are set so they turn on the light at around 5 psi. Not enough oil pressure to prevent problems at speed, but enought so not to turn on the light at idle. If your light came on while driveing some damage has been done, how much is hard to say. This is why all manuals say to check the oil before driveing, That means every day, sometime more then once a day.
At this point, all you can do is fill with the correct oil and montor the level and pressure. If it is low, then it is time for major engine work.
 

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Regettably it sounds like the "tech" at the "shop" didn't refill your engine oil. You're now burning oil because driving a few miles w/out oil pressure is like driving tens of thousands of miles with oil pressure...

Doing a compression test will reveal the damage to the rings.
There is no way to see the premature wear on the cam, rod, & crank bearings till you dissasemble the engine...

If the shop was a jiffy lube type place I would drain the oil out that you put in this morning and call the shop and tell them "I checked the oil this morning and the stick is dry. Send a tech over here to fill my oil!"
When they come to add your oil have you or someone with a video camera record the whole thing. While the tech is there start the engine and show how it's now burning oil. This may help you when you bring a civil suit against the shop that "destroyed" your engine...

If the "tech" worked at a real garage: Tell them the whole truth and maybe they'll meet you half way on fixing your car...

You are also at fault here (sorry to rub salt in the wound) as the operator for not checking the oil level as soon as you saw the light...
Your conscience will be your guide here as to what you do...
 

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Discussion Starter · #4 ·
Thank you for the responses Geoff and Banman.

The shop that changed my oil is a reputable Saab repair shop. FWIW I did see the quarts of oil sitting on the side of the engine compartment at one point when I happened to glance in during the service. I'm pretty sure that they refilled it. Especially considering I drove roughly 450 miles after the oil change without any issues whatsoever.

Unfortunately, due to the holiday, I'm not going to get in touch with anyone at the shop until tomorrow - if I'm lucky - possibly Monday.
 

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"Especially considering I drove roughly 450 miles after the oil change without any issues whatsoever."

That changes my response...

Still, to burn that much oil that quickly you should have noticed a cloud of smoke behind you while you drove.

It's possible an oil ring broke but the compression rings are still okay...
Or a head gasket failure...
Pulling the spark plugs should tell you something. If one or more plugs is oily you know there's an issue with that cylinder

And now to conjecture on tonights feast!

Good luck!
 

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have you checked you are not loosing oil at the filter, or the drain plug, as either could be a loss loser over 450mls and then hence the problem, but it's like watching your temp gauge getting into the red before you check if you are low on water, as with your oil light, it's self inflicted damage if that's what you find out, what's the poinrt of putting warning items on a car if you take no notice, never mind who's done the service a garage or yourself, as it's a always easy to be distracted and just forget to tighten something up.
hope it's not bad, but does'nt sound hopefull, but check the filter and plug(copper washer in place) tighness etc before anyone checks it, and then they tighten it, without you knowing as they messed up. but get away with it??
but if oil leak at filter there should be a lot on the inner body & engine parts and cross member etc etc
 

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If the oil fill cap/dipstick were loose it would spit out oil and idle poorly. It happened often back in the (8v) day.
 

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Discussion Starter · #8 ·
As I mentioned, no signs whatsoever of leaking at the plug or filter. Both were tight.

I did take a ride around town (20-25 minutes) looking for a mechanic on duty at a garage earlier today. No luck.

When I returned I let the car idle and checked for smoke - nothing. I put a white paper up to the exhaust pipe and no sign of any oil spewing out. Oil level appeared to be maintaining and no warning lights.

So... I was desperate to get somewhere and decided to chance taking a drive. The trip was 125 miles of almost all highway driving. Smooth sailing all the way. I stopped at the halfway point and checked the oil - no sign of additional loss - no sign of smoke. I'm baffled. Calling the shop in the morning.

Cheers,

Ryan
 

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Wrong oil ??

I can say the NG 900s 2.3 engines are almost bullet proof.

I know an owner who holed the sump on a rock, was out of cell phone range and drove for 15 mins at 40kmph with the big warning triangle and oil light on.

Fitted new sump, checked the bearings, put in a fresh lot of oil and filter, car is going just fine 30,000km later.

Here is hoping you have that kind of luck.

I can repeat a similar story on an engine in a Mitsubishi Mirage that survived a seize, freed up, and went on and on while we still owned it.

Female drivers!!

As far as I know it never burnt oil after the seize, and it had no engine knocks. Stange things like this sometimes happen.
 

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I can't imagine that much oil coming out the fill tube and not leaving the engine compartment a bloody mess!
No that wouldn't happen, wait till Jim comes back, but it will be to do with the emission system, and the oil being dragged through the combustion system.

It makes sense but I can not explain it.
 

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I can't imagine that much oil coming out the fill tube and not leaving the engine compartment a bloody mess!
I agree with Banman. Oil coming out of the filler tube will leave a "bloody mess" all around the top of the engine. It doesn't come out of an open filler tube anyway unless you have serious piston blowby. Any leak of this size would leave considerable mess around the leakage area. My first thought as to leak was filter seal and or drain plug. You say these were fine.

Other thoughts in the absence of engine mess, although long shots, are: oil not filled fully, wrong oil or EGR system, and if you had a turbo, turbo seals.

There's a fair chance that your engine is undamaged. The oil light does not come on until around 7 psi, and there probably was enough oil circulating to keep an oil film on the bearings, unless you were pushing it. These engines are fairly bullet-proof.

If your oil light remains out at idle on the engine when hot I think you may have got away with it, although you should have investigated when you first saw the oil light.
 

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You're all right.

The oil would not pump itself out the fill tube - as Banman says, you would see a royal mess under the hood if it did - but on the older cars, not having the oil cap on properly creates a vacuum leak that will cause the car to run like poo. And will probably drag oil through combustion.

O.P. probably hasn't done damage to the engine and the service guy who refilled his case probably didn't screw the cap on tight.
 

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You're all right.

The oil would not pump itself out the fill tube - as Banman says, you would see a royal mess under the hood if it did - but on the older cars, not having the oil cap on properly creates a vacuum leak that will cause the car to run like poo. And will probably drag oil through combustion.

O.P. probably hasn't done damage to the engine and the service guy who refilled his case probably didn't screw the cap on tight.
Hmmm? I still think burning 2 to 3 quarts of oil per ~450 miles would have left a noticable smoke cloud...

Rawill,
Will the 16v engine pull oil into the combustion chambers with the cap loose...?
 

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Hmmm? I still think burning 2 to 3 quarts of oil per ~450 miles would have left a noticable smoke cloud...

Rawill,
Will the 16v engine pull oil into the combustion chambers with the cap loose...?
I suspect so, I am no expert and I hope Jim M will come back and confirm this. Maybe send him a PM to confirm my suspicions. (I was a wrencher back in the late 60s-early 70s)

The clue for me is the running rough with the Filler cap off, and the oil dripping out the exhaust pipe. I suspect the oil was being sucked into the combustion system via the Emission control system, but that it wasn't all able to be burnt leaving residues in the exhaust system.

AND It would be very unusual for an engine to develop such incredible oil burning characteristics so suddenly, not impossible mind you. However, the fact that it started straight after someone worked on it (an oil change) points to something happening during that service.

When something is going fine, and then some work is done to the vehicle, and it seems to develop an issue from there, then go back to what was done and check check check.

I suspect the loose cap (running rough from the time you picked up the car) allowed vaccum to pull the oil through the combusition cycle. I believe this can happen to some extent with latter cars (I have 9000's) if the one way valve fails.
 

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1984 was a long time ago, and I retired in 1998. I don't remember the details of it, I only remember it was a common mistake. With an 8v, if anyone says 'checked my oil' or 'oil change', along with poor idle, it rings the bell.
Sometimes clean oil is hard to see when it escapes as a vapor. You can easily lose that amount through the dipstick in that mileage, it's a hurricane in there all the time; except it's oil instead of rain.
 

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SNIP...
Sometimes clean oil is hard to see when it escapes as a vapor. You can easily lose that amount through the dipstick in that mileage, it's a hurricane in there all the time; except it's oil instead of rain.
So the lost oil would be coming out of the top of the oil fill tube, past the loose cap? Not actually getting burned at all?
A thin vaporous spray about the engine compartment...

Would the 16v do this as well or not?
Just curious, not enough to try it as an experiment though...
 

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I don't think it would come up through the oil tube...3 to 4 qts of oil would definitely coat some vitals doing that. I think though, with a vacuum leak into the crankcase you could suck up half a thimble full through every couple full combustion cycles, 1 - 4, at 2200rpm, and lose 3 to 4 qts over 450 miles out the tailpipe without noticing a puff cloud.
 

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I don't think it would come up through the oil tube...3 to 4 qts of oil would definitely coat some vitals doing that. I think though, with a vacuum leak into the crankcase you could suck up half a thimble full through every couple full combustion cycles, 1 - 4, at 2200rpm, and lose 3 to 4 qts over 450 miles out the tailpipe without noticing a puff cloud.
The crankcase venting (loose oil cap) to atmosphere does not magicly cause the oil and compression rings to suddenly loose their seal...

I am not seeing a physical pathway for oil to find it's way into the combustion chamber because the oil cap is loose.

Are you saying a loose cap allows the engine (which is just a mechanical pump) to suck oil from the valve cover via the pcv tube into the intake and thus into the engine? This would be some serious "blowby"...

Glad to hear the engines are so well built though as to take some abuse without lasting issue.
 
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